drivers/media/v4l2-core/v4l2-dv-timings.c

   1 /*
   2  * v4l2-dv-timings - dv-timings helper functions
   3  *
   4  * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   5  *
   6  * This program is free software; you may redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  11  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  12  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  13  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  14  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  15  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  16  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  17  * SOFTWARE.
  18  *
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/kernel.h>
  24 #include <linux/errno.h>
  25 #include <linux/videodev2.h>
  26 #include <linux/v4l2-dv-timings.h>
  27 #include <media/v4l2-dv-timings.h>
  28 #include <linux/math64.h>
  29
  30 MODULE_AUTHOR("Hans Verkuil");
  31 MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions");
  32 MODULE_LICENSE("GPL");
  33
  34 const struct v4l2_dv_timings v4l2_dv_timings_presets[] = {
  35         V4L2_DV_BT_CEA_640X480P59_94,
  36         V4L2_DV_BT_CEA_720X480I59_94,
  37         V4L2_DV_BT_CEA_720X480P59_94,
  38         V4L2_DV_BT_CEA_720X576I50,
  39         V4L2_DV_BT_CEA_720X576P50,
  40         V4L2_DV_BT_CEA_1280X720P24,
  41         V4L2_DV_BT_CEA_1280X720P25,
  42         V4L2_DV_BT_CEA_1280X720P30,
  43         V4L2_DV_BT_CEA_1280X720P50,
  44         V4L2_DV_BT_CEA_1280X720P60,
  45         V4L2_DV_BT_CEA_1920X1080P24,
  46         V4L2_DV_BT_CEA_1920X1080P25,
  47         V4L2_DV_BT_CEA_1920X1080P30,
  48         V4L2_DV_BT_CEA_1920X1080I50,
  49         V4L2_DV_BT_CEA_1920X1080P50,
  50         V4L2_DV_BT_CEA_1920X1080I60,
  51         V4L2_DV_BT_CEA_1920X1080P60,
  52         V4L2_DV_BT_DMT_640X350P85,
  53         V4L2_DV_BT_DMT_640X400P85,
  54         V4L2_DV_BT_DMT_720X400P85,
  55         V4L2_DV_BT_DMT_640X480P72,
  56         V4L2_DV_BT_DMT_640X480P75,
  57         V4L2_DV_BT_DMT_640X480P85,
  58         V4L2_DV_BT_DMT_800X600P56,
  59         V4L2_DV_BT_DMT_800X600P60,
  60         V4L2_DV_BT_DMT_800X600P72,
  61         V4L2_DV_BT_DMT_800X600P75,
  62         V4L2_DV_BT_DMT_800X600P85,
  63         V4L2_DV_BT_DMT_800X600P120_RB,
  64         V4L2_DV_BT_DMT_848X480P60,
  65         V4L2_DV_BT_DMT_1024X768I43,
  66         V4L2_DV_BT_DMT_1024X768P60,
  67         V4L2_DV_BT_DMT_1024X768P70,
  68         V4L2_DV_BT_DMT_1024X768P75,
  69         V4L2_DV_BT_DMT_1024X768P85,
  70         V4L2_DV_BT_DMT_1024X768P120_RB,
  71         V4L2_DV_BT_DMT_1152X864P75,
  72         V4L2_DV_BT_DMT_1280X768P60_RB,
  73         V4L2_DV_BT_DMT_1280X768P60,
  74         V4L2_DV_BT_DMT_1280X768P75,
  75         V4L2_DV_BT_DMT_1280X768P85,
  76         V4L2_DV_BT_DMT_1280X768P120_RB,
  77         V4L2_DV_BT_DMT_1280X800P60_RB,
  78         V4L2_DV_BT_DMT_1280X800P60,
  79         V4L2_DV_BT_DMT_1280X800P75,
  80         V4L2_DV_BT_DMT_1280X800P85,
  81         V4L2_DV_BT_DMT_1280X800P120_RB,
  82         V4L2_DV_BT_DMT_1280X960P60,
  83         V4L2_DV_BT_DMT_1280X960P85,
  84         V4L2_DV_BT_DMT_1280X960P120_RB,
  85         V4L2_DV_BT_DMT_1280X1024P60,
  86         V4L2_DV_BT_DMT_1280X1024P75,
  87         V4L2_DV_BT_DMT_1280X1024P85,
  88         V4L2_DV_BT_DMT_1280X1024P120_RB,
  89         V4L2_DV_BT_DMT_1360X768P60,
  90         V4L2_DV_BT_DMT_1360X768P120_RB,
  91         V4L2_DV_BT_DMT_1366X768P60,
  92         V4L2_DV_BT_DMT_1366X768P60_RB,
  93         V4L2_DV_BT_DMT_1400X1050P60_RB,
  94         V4L2_DV_BT_DMT_1400X1050P60,
  95         V4L2_DV_BT_DMT_1400X1050P75,
  96         V4L2_DV_BT_DMT_1400X1050P85,
  97         V4L2_DV_BT_DMT_1400X1050P120_RB,
  98         V4L2_DV_BT_DMT_1440X900P60_RB,
  99         V4L2_DV_BT_DMT_1440X900P60,
 100         V4L2_DV_BT_DMT_1440X900P75,
 101         V4L2_DV_BT_DMT_1440X900P85,
 102         V4L2_DV_BT_DMT_1440X900P120_RB,
 103         V4L2_DV_BT_DMT_1600X900P60_RB,
 104         V4L2_DV_BT_DMT_1600X1200P60,
 105         V4L2_DV_BT_DMT_1600X1200P65,
 106         V4L2_DV_BT_DMT_1600X1200P70,
 107         V4L2_DV_BT_DMT_1600X1200P75,
 108         V4L2_DV_BT_DMT_1600X1200P85,
 109         V4L2_DV_BT_DMT_1600X1200P120_RB,
 110         V4L2_DV_BT_DMT_1680X1050P60_RB,
 111         V4L2_DV_BT_DMT_1680X1050P60,
 112         V4L2_DV_BT_DMT_1680X1050P75,
 113         V4L2_DV_BT_DMT_1680X1050P85,
 114         V4L2_DV_BT_DMT_1680X1050P120_RB,
 115         V4L2_DV_BT_DMT_1792X1344P60,
 116         V4L2_DV_BT_DMT_1792X1344P75,
 117         V4L2_DV_BT_DMT_1792X1344P120_RB,
 118         V4L2_DV_BT_DMT_1856X1392P60,
 119         V4L2_DV_BT_DMT_1856X1392P75,
 120         V4L2_DV_BT_DMT_1856X1392P120_RB,
 121         V4L2_DV_BT_DMT_1920X1200P60_RB,
 122         V4L2_DV_BT_DMT_1920X1200P60,
 123         V4L2_DV_BT_DMT_1920X1200P75,
 124         V4L2_DV_BT_DMT_1920X1200P85,
 125         V4L2_DV_BT_DMT_1920X1200P120_RB,
 126         V4L2_DV_BT_DMT_1920X1440P60,
 127         V4L2_DV_BT_DMT_1920X1440P75,
 128         V4L2_DV_BT_DMT_1920X1440P120_RB,
 129         V4L2_DV_BT_DMT_2048X1152P60_RB,
 130         V4L2_DV_BT_DMT_2560X1600P60_RB,
 131         V4L2_DV_BT_DMT_2560X1600P60,
 132         V4L2_DV_BT_DMT_2560X1600P75,
 133         V4L2_DV_BT_DMT_2560X1600P85,
 134         V4L2_DV_BT_DMT_2560X1600P120_RB,
 135         V4L2_DV_BT_CEA_3840X2160P24,
 136         V4L2_DV_BT_CEA_3840X2160P25,
 137         V4L2_DV_BT_CEA_3840X2160P30,
 138         V4L2_DV_BT_CEA_3840X2160P50,
 139         V4L2_DV_BT_CEA_3840X2160P60,
 140         V4L2_DV_BT_CEA_4096X2160P24,
 141         V4L2_DV_BT_CEA_4096X2160P25,
 142         V4L2_DV_BT_CEA_4096X2160P30,
 143         V4L2_DV_BT_CEA_4096X2160P50,
 144         V4L2_DV_BT_DMT_4096X2160P59_94_RB,
 145         V4L2_DV_BT_CEA_4096X2160P60,
 146         { }
 147 };
 148 EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
 149
 150 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
 151                            const struct v4l2_dv_timings_cap *dvcap,
 152                            v4l2_check_dv_timings_fnc fnc,
 153                            void *fnc_handle)
 154 {
 155         const struct v4l2_bt_timings *bt = &t->bt;
 156         const struct v4l2_bt_timings_cap *cap = &dvcap->bt;
 157         u32 caps = cap->capabilities;
 158
 159         if (t->type != V4L2_DV_BT_656_1120)
 160                 return false;
 161         if (t->type != dvcap->type ||
 162             bt->height < cap->min_height ||
 163             bt->height > cap->max_height ||
 164             bt->width < cap->min_width ||
 165             bt->width > cap->max_width ||
 166             bt->pixelclock < cap->min_pixelclock ||
 167             bt->pixelclock > cap->max_pixelclock ||
 168             (cap->standards && bt->standards &&
 169              !(bt->standards & cap->standards)) ||
 170             (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
 171             (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
 172                 return false;
 173         return fnc == NULL || fnc(t, fnc_handle);
 174 }
 175 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
 176
 177 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
 178                              const struct v4l2_dv_timings_cap *cap,
 179                              v4l2_check_dv_timings_fnc fnc,
 180                              void *fnc_handle)
 181 {
 182         u32 i, idx;
 183
 184         memset(t->reserved, 0, sizeof(t->reserved));
 185         for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) {
 186                 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
 187                                           fnc, fnc_handle) &&
 188                     idx++ == t->index) {
 189                         t->timings = v4l2_dv_timings_presets[i];
 190                         return 0;
 191                 }
 192         }
 193         return -EINVAL;
 194 }
 195 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
 196
 197 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
 198                               const struct v4l2_dv_timings_cap *cap,
 199                               unsigned pclock_delta,
 200                               v4l2_check_dv_timings_fnc fnc,
 201                               void *fnc_handle)
 202 {
 203         int i;
 204
 205         if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle))
 206                 return false;
 207
 208         for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
 209                 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
 210                                           fnc, fnc_handle) &&
 211                     v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i,
 212                                           pclock_delta, false)) {
 213                         u32 flags = t->bt.flags & V4L2_DV_FL_REDUCED_FPS;
 214
 215                         *t = v4l2_dv_timings_presets[i];
 216                         if (can_reduce_fps(&t->bt))
 217                                 t->bt.flags |= flags;
 218
 219                         return true;
 220                 }
 221         }
 222         return false;
 223 }
 224 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
 225
 226 /**
 227  * v4l2_match_dv_timings - check if two timings match
 228  * @t1 - compare this v4l2_dv_timings struct...
 229  * @t2 - with this struct.
 230  * @pclock_delta - the allowed pixelclock deviation.
 231  * @match_reduced_fps - if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
 232  * match.
 233  *
 234  * Compare t1 with t2 with a given margin of error for the pixelclock.
 235  */
 236 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
 237                            const struct v4l2_dv_timings *t2,
 238                            unsigned pclock_delta, bool match_reduced_fps)
 239 {
 240         if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
 241                 return false;
 242         if (t1->bt.width == t2->bt.width &&
 243             t1->bt.height == t2->bt.height &&
 244             t1->bt.interlaced == t2->bt.interlaced &&
 245             t1->bt.polarities == t2->bt.polarities &&
 246             t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
 247             t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
 248             t1->bt.hfrontporch == t2->bt.hfrontporch &&
 249             t1->bt.hsync == t2->bt.hsync &&
 250             t1->bt.hbackporch == t2->bt.hbackporch &&
 251             t1->bt.vfrontporch == t2->bt.vfrontporch &&
 252             t1->bt.vsync == t2->bt.vsync &&
 253             t1->bt.vbackporch == t2->bt.vbackporch &&
 254             (!match_reduced_fps ||
 255              (t1->bt.flags & V4L2_DV_FL_REDUCED_FPS) ==
 256                 (t2->bt.flags & V4L2_DV_FL_REDUCED_FPS)) &&
 257             (!t1->bt.interlaced ||
 258                 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
 259                  t1->bt.il_vsync == t2->bt.il_vsync &&
 260                  t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
 261                 return true;
 262         return false;
 263 }
 264 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
 265
 266 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
 267                            const struct v4l2_dv_timings *t, bool detailed)
 268 {
 269         const struct v4l2_bt_timings *bt = &t->bt;
 270         u32 htot, vtot;
 271         u32 fps;
 272
 273         if (t->type != V4L2_DV_BT_656_1120)
 274                 return;
 275
 276         htot = V4L2_DV_BT_FRAME_WIDTH(bt);
 277         vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
 278         if (bt->interlaced)
 279                 vtot /= 2;
 280
 281         fps = (htot * vtot) > 0 ? div_u64((100 * (u64)bt->pixelclock),
 282                                   (htot * vtot)) : 0;
 283
 284         if (prefix == NULL)
 285                 prefix = "";
 286
 287         pr_info("%s: %s%ux%u%s%u.%u (%ux%u)\n", dev_prefix, prefix,
 288                 bt->width, bt->height, bt->interlaced ? "i" : "p",
 289                 fps / 100, fps % 100, htot, vtot);
 290
 291         if (!detailed)
 292                 return;
 293
 294         pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
 295                         dev_prefix, bt->hfrontporch,
 296                         (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
 297                         bt->hsync, bt->hbackporch);
 298         pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
 299                         dev_prefix, bt->vfrontporch,
 300                         (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
 301                         bt->vsync, bt->vbackporch);
 302         if (bt->interlaced)
 303                 pr_info("%s: vertical bottom field: fp = %u, %ssync = %u, bp = %u\n",
 304                         dev_prefix, bt->il_vfrontporch,
 305                         (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
 306                         bt->il_vsync, bt->il_vbackporch);
 307         pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
 308         pr_info("%s: flags (0x%x):%s%s%s%s%s%s\n", dev_prefix, bt->flags,
 309                         (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
 310                         " REDUCED_BLANKING" : "",
 311                         ((bt->flags & V4L2_DV_FL_REDUCED_BLANKING) &&
 312                          bt->vsync == 8) ? " (V2)" : "",
 313                         (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
 314                         " CAN_REDUCE_FPS" : "",
 315                         (bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
 316                         " REDUCED_FPS" : "",
 317                         (bt->flags & V4L2_DV_FL_HALF_LINE) ?
 318                         " HALF_LINE" : "",
 319                         (bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ?
 320                         " CE_VIDEO" : "");
 321         pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards,
 322                         (bt->standards & V4L2_DV_BT_STD_CEA861) ?  " CEA" : "",
 323                         (bt->standards & V4L2_DV_BT_STD_DMT) ?  " DMT" : "",
 324                         (bt->standards & V4L2_DV_BT_STD_CVT) ?  " CVT" : "",
 325                         (bt->standards & V4L2_DV_BT_STD_GTF) ?  " GTF" : "");
 326 }
 327 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
 328
 329 /*
 330  * CVT defines
 331  * Based on Coordinated Video Timings Standard
 332  * version 1.1 September 10, 2003
 333  */
 334
 335 #define CVT_PXL_CLK_GRAN        250000  /* pixel clock granularity */
 336 #define CVT_PXL_CLK_GRAN_RB_V2 1000     /* granularity for reduced blanking v2*/
 337
 338 /* Normal blanking */
 339 #define CVT_MIN_V_BPORCH        7       /* lines */
 340 #define CVT_MIN_V_PORCH_RND     3       /* lines */
 341 #define CVT_MIN_VSYNC_BP        550     /* min time of vsync + back porch (us) */
 342 #define CVT_HSYNC_PERCENT       8       /* nominal hsync as percentage of line */
 343
 344 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */
 345 #define CVT_CELL_GRAN           8       /* character cell granularity */
 346 #define CVT_M                   600     /* blanking formula gradient */
 347 #define CVT_C                   40      /* blanking formula offset */
 348 #define CVT_K                   128     /* blanking formula scaling factor */
 349 #define CVT_J                   20      /* blanking formula scaling factor */
 350 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
 351 #define CVT_M_PRIME (CVT_K * CVT_M / 256)
 352
 353 /* Reduced Blanking */
 354 #define CVT_RB_MIN_V_BPORCH    7       /* lines  */
 355 #define CVT_RB_V_FPORCH        3       /* lines  */
 356 #define CVT_RB_MIN_V_BLANK   460       /* us     */
 357 #define CVT_RB_H_SYNC         32       /* pixels */
 358 #define CVT_RB_H_BLANK       160       /* pixels */
 359 /* Reduce blanking Version 2 */
 360 #define CVT_RB_V2_H_BLANK     80       /* pixels */
 361 #define CVT_RB_MIN_V_FPORCH    3       /* lines  */
 362 #define CVT_RB_V2_MIN_V_FPORCH 1       /* lines  */
 363 #define CVT_RB_V_BPORCH        6       /* lines  */
 364
 365 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard
 366  * @frame_height - the total height of the frame (including blanking) in lines.
 367  * @hfreq - the horizontal frequency in Hz.
 368  * @vsync - the height of the vertical sync in lines.
 369  * @active_width - active width of image (does not include blanking). This
 370  * information is needed only in case of version 2 of reduced blanking.
 371  * In other cases, this parameter does not have any effect on timings.
 372  * @polarities - the horizontal and vertical polarities (same as struct
 373  *              v4l2_bt_timings polarities).
 374  * @interlaced - if this flag is true, it indicates interlaced format
 375  * @fmt - the resulting timings.
 376  *
 377  * This function will attempt to detect if the given values correspond to a
 378  * valid CVT format. If so, then it will return true, and fmt will be filled
 379  * in with the found CVT timings.
 380  */
 381 bool v4l2_detect_cvt(unsigned frame_height,
 382                      unsigned hfreq,
 383                      unsigned vsync,
 384                      unsigned active_width,
 385                      u32 polarities,
 386                      bool interlaced,
 387                      struct v4l2_dv_timings *fmt)
 388 {
 389         int  v_fp, v_bp, h_fp, h_bp, hsync;
 390         int  frame_width, image_height, image_width;
 391         bool reduced_blanking;
 392         bool rb_v2 = false;
 393         unsigned pix_clk;
 394
 395         if (vsync < 4 || vsync > 8)
 396                 return false;
 397
 398         if (polarities == V4L2_DV_VSYNC_POS_POL)
 399                 reduced_blanking = false;
 400         else if (polarities == V4L2_DV_HSYNC_POS_POL)
 401                 reduced_blanking = true;
 402         else
 403                 return false;
 404
 405         if (reduced_blanking && vsync == 8)
 406                 rb_v2 = true;
 407
 408         if (rb_v2 && active_width == 0)
 409                 return false;
 410
 411         if (!rb_v2 && vsync > 7)
 412                 return false;
 413
 414         if (hfreq == 0)
 415                 return false;
 416
 417         /* Vertical */
 418         if (reduced_blanking) {
 419                 if (rb_v2) {
 420                         v_bp = CVT_RB_V_BPORCH;
 421                         v_fp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
 422                         v_fp -= vsync + v_bp;
 423
 424                         if (v_fp < CVT_RB_V2_MIN_V_FPORCH)
 425                                 v_fp = CVT_RB_V2_MIN_V_FPORCH;
 426                 } else {
 427                         v_fp = CVT_RB_V_FPORCH;
 428                         v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
 429                         v_bp -= vsync + v_fp;
 430
 431                         if (v_bp < CVT_RB_MIN_V_BPORCH)
 432                                 v_bp = CVT_RB_MIN_V_BPORCH;
 433                 }
 434         } else {
 435                 v_fp = CVT_MIN_V_PORCH_RND;
 436                 v_bp = (CVT_MIN_VSYNC_BP * hfreq) / 1000000 + 1 - vsync;
 437
 438                 if (v_bp < CVT_MIN_V_BPORCH)
 439                         v_bp = CVT_MIN_V_BPORCH;
 440         }
 441
 442         if (interlaced)
 443                 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
 444         else
 445                 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
 446
 447         if (image_height < 0)
 448                 return false;
 449
 450         /* Aspect ratio based on vsync */
 451         switch (vsync) {
 452         case 4:
 453                 image_width = (image_height * 4) / 3;
 454                 break;
 455         case 5:
 456                 image_width = (image_height * 16) / 9;
 457                 break;
 458         case 6:
 459                 image_width = (image_height * 16) / 10;
 460                 break;
 461         case 7:
 462                 /* special case */
 463                 if (image_height == 1024)
 464                         image_width = (image_height * 5) / 4;
 465                 else if (image_height == 768)
 466                         image_width = (image_height * 15) / 9;
 467                 else
 468                         return false;
 469                 break;
 470         case 8:
 471                 image_width = active_width;
 472                 break;
 473         default:
 474                 return false;
 475         }
 476
 477         if (!rb_v2)
 478                 image_width = image_width & ~7;
 479
 480         /* Horizontal */
 481         if (reduced_blanking) {
 482                 int h_blank;
 483                 int clk_gran;
 484
 485                 h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK;
 486                 clk_gran = rb_v2 ? CVT_PXL_CLK_GRAN_RB_V2 : CVT_PXL_CLK_GRAN;
 487
 488                 pix_clk = (image_width + h_blank) * hfreq;
 489                 pix_clk = (pix_clk / clk_gran) * clk_gran;
 490
 491                 h_bp  = h_blank / 2;
 492                 hsync = CVT_RB_H_SYNC;
 493                 h_fp  = h_blank - h_bp - hsync;
 494
 495                 frame_width = image_width + h_blank;
 496         } else {
 497                 unsigned ideal_duty_cycle_per_myriad =
 498                         100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
 499                 int h_blank;
 500
 501                 if (ideal_duty_cycle_per_myriad < 2000)
 502                         ideal_duty_cycle_per_myriad = 2000;
 503
 504                 h_blank = image_width * ideal_duty_cycle_per_myriad /
 505                                         (10000 - ideal_duty_cycle_per_myriad);
 506                 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;
 507
 508                 pix_clk = (image_width + h_blank) * hfreq;
 509                 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
 510
 511                 h_bp = h_blank / 2;
 512                 frame_width = image_width + h_blank;
 513
 514                 hsync = frame_width * CVT_HSYNC_PERCENT / 100;
 515                 hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN;
 516                 h_fp = h_blank - hsync - h_bp;
 517         }
 518
 519         fmt->type = V4L2_DV_BT_656_1120;
 520         fmt->bt.polarities = polarities;
 521         fmt->bt.width = image_width;
 522         fmt->bt.height = image_height;
 523         fmt->bt.hfrontporch = h_fp;
 524         fmt->bt.vfrontporch = v_fp;
 525         fmt->bt.hsync = hsync;
 526         fmt->bt.vsync = vsync;
 527         fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
 528
 529         if (!interlaced) {
 530                 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
 531                 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
 532         } else {
 533                 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
 534                                       2 * vsync) / 2;
 535                 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
 536                                         2 * vsync - fmt->bt.vbackporch;
 537                 fmt->bt.il_vfrontporch = v_fp;
 538                 fmt->bt.il_vsync = vsync;
 539                 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
 540                 fmt->bt.interlaced = V4L2_DV_INTERLACED;
 541         }
 542
 543         fmt->bt.pixelclock = pix_clk;
 544         fmt->bt.standards = V4L2_DV_BT_STD_CVT;
 545
 546         if (reduced_blanking)
 547                 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
 548
 549         return true;
 550 }
 551 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
 552
 553 /*
 554  * GTF defines
 555  * Based on Generalized Timing Formula Standard
 556  * Version 1.1 September 2, 1999
 557  */
 558
 559 #define GTF_PXL_CLK_GRAN        250000  /* pixel clock granularity */
 560
 561 #define GTF_MIN_VSYNC_BP        550     /* min time of vsync + back porch (us) */
 562 #define GTF_V_FP                1       /* vertical front porch (lines) */
 563 #define GTF_CELL_GRAN           8       /* character cell granularity */
 564
 565 /* Default */
 566 #define GTF_D_M                 600     /* blanking formula gradient */
 567 #define GTF_D_C                 40      /* blanking formula offset */
 568 #define GTF_D_K                 128     /* blanking formula scaling factor */
 569 #define GTF_D_J                 20      /* blanking formula scaling factor */
 570 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
 571 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
 572
 573 /* Secondary */
 574 #define GTF_S_M                 3600    /* blanking formula gradient */
 575 #define GTF_S_C                 40      /* blanking formula offset */
 576 #define GTF_S_K                 128     /* blanking formula scaling factor */
 577 #define GTF_S_J                 35      /* blanking formula scaling factor */
 578 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
 579 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
 580
 581 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
 582  * @frame_height - the total height of the frame (including blanking) in lines.
 583  * @hfreq - the horizontal frequency in Hz.
 584  * @vsync - the height of the vertical sync in lines.
 585  * @polarities - the horizontal and vertical polarities (same as struct
 586  *              v4l2_bt_timings polarities).
 587  * @interlaced - if this flag is true, it indicates interlaced format
 588  * @aspect - preferred aspect ratio. GTF has no method of determining the
 589  *              aspect ratio in order to derive the image width from the
 590  *              image height, so it has to be passed explicitly. Usually
 591  *              the native screen aspect ratio is used for this. If it
 592  *              is not filled in correctly, then 16:9 will be assumed.
 593  * @fmt - the resulting timings.
 594  *
 595  * This function will attempt to detect if the given values correspond to a
 596  * valid GTF format. If so, then it will return true, and fmt will be filled
 597  * in with the found GTF timings.
 598  */
 599 bool v4l2_detect_gtf(unsigned frame_height,
 600                 unsigned hfreq,
 601                 unsigned vsync,
 602                 u32 polarities,
 603                 bool interlaced,
 604                 struct v4l2_fract aspect,
 605                 struct v4l2_dv_timings *fmt)
 606 {
 607         int pix_clk;
 608         int  v_fp, v_bp, h_fp, hsync;
 609         int frame_width, image_height, image_width;
 610         bool default_gtf;
 611         int h_blank;
 612
 613         if (vsync != 3)
 614                 return false;
 615
 616         if (polarities == V4L2_DV_VSYNC_POS_POL)
 617                 default_gtf = true;
 618         else if (polarities == V4L2_DV_HSYNC_POS_POL)
 619                 default_gtf = false;
 620         else
 621                 return false;
 622
 623         if (hfreq == 0)
 624                 return false;
 625
 626         /* Vertical */
 627         v_fp = GTF_V_FP;
 628         v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync;
 629         if (interlaced)
 630                 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
 631         else
 632                 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
 633
 634         if (image_height < 0)
 635                 return false;
 636
 637         if (aspect.numerator == 0 || aspect.denominator == 0) {
 638                 aspect.numerator = 16;
 639                 aspect.denominator = 9;
 640         }
 641         image_width = ((image_height * aspect.numerator) / aspect.denominator);
 642         image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
 643
 644         /* Horizontal */
 645         if (default_gtf) {
 646                 u64 num;
 647                 u32 den;
 648
 649                 num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) -
 650                       ((u64)image_width * GTF_D_M_PRIME * 1000));
 651                 den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) *
 652                       (2 * GTF_CELL_GRAN);
 653                 h_blank = div_u64((num + (den >> 1)), den);
 654                 h_blank *= (2 * GTF_CELL_GRAN);
 655         } else {
 656                 u64 num;
 657                 u32 den;
 658
 659                 num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) -
 660                       ((u64)image_width * GTF_S_M_PRIME * 1000));
 661                 den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) *
 662                       (2 * GTF_CELL_GRAN);
 663                 h_blank = div_u64((num + (den >> 1)), den);
 664                 h_blank *= (2 * GTF_CELL_GRAN);
 665         }
 666
 667         frame_width = image_width + h_blank;
 668
 669         pix_clk = (image_width + h_blank) * hfreq;
 670         pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
 671
 672         hsync = (frame_width * 8 + 50) / 100;
 673         hsync = ((hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN;
 674
 675         h_fp = h_blank / 2 - hsync;
 676
 677         fmt->type = V4L2_DV_BT_656_1120;
 678         fmt->bt.polarities = polarities;
 679         fmt->bt.width = image_width;
 680         fmt->bt.height = image_height;
 681         fmt->bt.hfrontporch = h_fp;
 682         fmt->bt.vfrontporch = v_fp;
 683         fmt->bt.hsync = hsync;
 684         fmt->bt.vsync = vsync;
 685         fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
 686
 687         if (!interlaced) {
 688                 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
 689                 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
 690         } else {
 691                 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
 692                                       2 * vsync) / 2;
 693                 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
 694                                         2 * vsync - fmt->bt.vbackporch;
 695                 fmt->bt.il_vfrontporch = v_fp;
 696                 fmt->bt.il_vsync = vsync;
 697                 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
 698                 fmt->bt.interlaced = V4L2_DV_INTERLACED;
 699         }
 700
 701         fmt->bt.pixelclock = pix_clk;
 702         fmt->bt.standards = V4L2_DV_BT_STD_GTF;
 703
 704         if (!default_gtf)
 705                 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
 706
 707         return true;
 708 }
 709 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
 710
 711 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
 712  *      0x15 and 0x16 from the EDID.
 713  * @hor_landscape - byte 0x15 from the EDID.
 714  * @vert_portrait - byte 0x16 from the EDID.
 715  *
 716  * Determines the aspect ratio from the EDID.
 717  * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
 718  * "Horizontal and Vertical Screen Size or Aspect Ratio"
 719  */
 720 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
 721 {
 722         struct v4l2_fract aspect = { 16, 9 };
 723         u8 ratio;
 724
 725         /* Nothing filled in, fallback to 16:9 */
 726         if (!hor_landscape && !vert_portrait)
 727                 return aspect;
 728         /* Both filled in, so they are interpreted as the screen size in cm */
 729         if (hor_landscape && vert_portrait) {
 730                 aspect.numerator = hor_landscape;
 731                 aspect.denominator = vert_portrait;
 732                 return aspect;
 733         }
 734         /* Only one is filled in, so interpret them as a ratio:
 735            (val + 99) / 100 */
 736         ratio = hor_landscape | vert_portrait;
 737         /* Change some rounded values into the exact aspect ratio */
 738         if (ratio == 79) {
 739                 aspect.numerator = 16;
 740                 aspect.denominator = 9;
 741         } else if (ratio == 34) {
 742                 aspect.numerator = 4;
 743                 aspect.denominator = 3;
 744         } else if (ratio == 68) {
 745                 aspect.numerator = 15;
 746                 aspect.denominator = 9;
 747         } else {
 748                 aspect.numerator = hor_landscape + 99;
 749                 aspect.denominator = 100;
 750         }
 751         if (hor_landscape)
 752                 return aspect;
 753         /* The aspect ratio is for portrait, so swap numerator and denominator */
 754         swap(aspect.denominator, aspect.numerator);
 755         return aspect;
 756 }
 757 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);